Fosfomycin trometamol, which chemical name is mono(2-ammonium-2-hydroxymethyl-1,3-propanediol) (2R,cis)-(3-methyloxiranyl)phosphonate, is an antibiotic indicated in the prophylaxis and treatment of uncomplicated acute infections of the lower urinary tract.
There are some fosfomycin trometamol pharmaceutical compositions for oral administration disclosed in the state of the art.
The Spanish patent application ES495870 (Zambon, S.p.a.) describes a composition for oral administration in form of sachets containing fosfomycin trometamol, sodium carboxymethylcellulose, lactose, titanium dioxide, orange flavour and sucrose. The sucrose content in this composition, depending on the active substance dosage, changes between 56 and 76% as weight of the total composition.
Another Spanish patent application, ES 2020790 (Zambon Group, S.p.a.), discloses a granulated containing fosfomycin trometamol, saccharine, flavour and sucrose. The sucrose content in this composition comprises 28% as weight of the total composition.
The Spanish patent application ES2224869 (Zambon Group, S.p.a.) discloses the use of certain basic compounds to stabilize a fosfomycin trometamol pharmaceutical composition. Some compositions described in the examples also mention the use of between 16% and 22% of sucrose as weight of the total composition.
The Spanish patent application ES2244333 (Simbec Ibérica, S. L.) discloses a pharmaceutical preparation comprising fosfomycin trometamol, mannitol and/or xylitol and an artificial sweetening agent selected from the group including acesulfame, aspartame, saccharin, alitame and/or cyclamate. The mannitol and/or xylitol content comprises between 20-40% as weight of the total composition.
The presence of certain sugars such as sucrose, fructose or glucose in a fosfomycin trometamol pharmaceutical composition can arise in an undesirable colouration due to the reaction between the aldehyde groups of such sugars with the trometamol amine or any other primary amino group present in the composition. Furthermore, the presence of these sugars makes the obtained pharmaceutical composition not suitable for the administration to diabetic patients.
On the other hand, it is well known in the state of the art that pharmaceutical compositions comprising a sugar derivative such as a sugar alcohol, in particular xylitol, mannitol, sorbitol or mixtures thereof, can cause intestinal problems such as an undesirable laxative effect or abdominals gases.